1. Field of the Invention
The present invention relates to a socket for a semiconductor device.
2. Description of the Related Art
In semiconductor devices that serve as electronic apparatuses mounted in electronics equipment, testing in order to eliminate latent defects at a stage before mounting is generally carried out via a semiconductor device socket. Semiconductor device sockets that are used in such tests, and that are provided for mounting, are generally referred to as IC sockets, and are disposed on printed circuited boards (test boards or boards for actual mounting), such as those shown in Japanese Patent Laid-Open No. 2005-156530, for example.
In the case where a semiconductor device socket is provided in a transmission path where a RF signal of a comparatively high, for example 1 GHz or greater, frequency band, is transmitted, it is known that transmission performance of signals of a comparatively high frequency band is raised by way of minimizing the length between the contact points of the movable terminal parts of the contact terminals and the base of their soldered fixation terminals, and decreasing impedance, along with implementing impedance matching in order to raise the transmission characteristics of the comparatively high frequency band at the IC socket.
And, with respect to IC sockets, as illustrated at FIG. 9 of Japanese Patent Laid-Open No. 2005-156530, for example, a device is proposed that is configured to include a holder substrate, which comprises a first substrate and a second substrate that are superimposed with respect to each other, and a plurality of contacts that are received in the respective openings inside the first substrate and the second substrate.
In the configuration above the holder substrate is made from a conductive material which has been subjected to surface processing. And contacts for each signal line that comprise so-called spring probes, etc., are separately received through an insulating pipe member into respective openings that correspond to prescribed signal lines of a semiconductor device serving as a testing object and that penetrate through the thickness direction of the holder substrate, for example.
Accordingly, the impedance of signal lines that transmit high frequency electric signals is adjusted to a prescribed value, along with attenuation of the transmitted signal being restrained because it is possible to increase the outer diameter of the contacts for the respective signal lines. In doing so, respective openings are formed that correspond to prescribed ground lines and power-supply lines of the semiconductor device, at locations that are adjacent to the respective openings in which each of the signal contacts are received, with prescribed spaces therebetween. Contacts, for earthing, which have maximum diameters greater than the maximum diameters of the signal contacts, and contacts, for feeding, which have diameters that are the same as the diameters of the signal contacts, are received inside respective openings.
Earthing contact terminals are received inside openings through conductive pipe members. And feeding contacts are received inside openings through insulating pipe members. As mentioned above, the maximum diameters of earthing contacts are set large in comparison to the maximum diameters of signal contacts and feeding contacts.
Furthermore, as shown at FIGS. 2 and 8 of Japanese Patent Laid-Open No. 2005-156530, a device is proposed in which only signal, earthing and feeding contacts that have the same diameter as each other are received in respective openings. And also, a device is proposed wherein a signal contact, an earthing contact and a feeding contact, which have the same diameter as each other, are each received in respective housings through an impedance adjusting member.
In the case where the impedances is mismatched it is desirable that the thicknesses of the first substrate and the second substrate be constructed as thin as possible. And, in the case where the quantity of contacts is increased in accordance with an increase in the number of electrodes at the electrode portion of the semiconductor device, it is desirable that the magnitudes of the flexural rigidities of the first substrate and the second substrate be set to a value such as not to decrease positional accuracy of the plurality of contacts and such that the first and second substrates do not warp.